Java简单网上购物小项目

package s2jsp.bysj.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.ArrayList; import java.util.List; import s2jsp.bysj.entity.Product; public class ProductDao extends BaseDao { private Connection conn = null; private PreparedStatement pstmt = null; private ResultSet rs = null; public List findAllByType(String type) { List list = null; String sql = "select * from product where type=?"; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); pstmt.setString(1, type); rs = pstmt.executeQuery(); list = new ArrayList(); while (rs.next()) { Product product = new Product(); product.setProductID(rs.getInt("productId")); product.setName(rs.getString("name")); product.setBrand(rs.getString("brand")); product.setPrice(rs.getFloat("price"));// 问题待解 product.setPicture(rs.getString("picture")); product.setDescription(rs.getString("description")); list.add(product); } } catch (Exception e) { e.printStackTrace(); } return list; } public Product finadProductById(int productId) { String sql = "select * from product where productid=?"; Product product = null; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); pstmt.setInt(1, productId); rs = pstmt.executeQuery(); if (rs.next()) { product = new Product(); product.setProductID(rs.getInt("productId")); product.setName(rs.getString("name")); product.setBrand(rs.getString("brand")); product.setPrice(rs.getFloat("price")); product.setPicture(rs.getString("picture")); product.setDescription(rs.getString("description")); product.setType(rs.getString("type")); } } catch (Exception e) { e.printStackTrace(); } return product; } public List findProductByType(String type) { List list = null; String sql = "select top 3 * from product where type=?"; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); pstmt.setString(1, type); rs = pstmt.executeQuery(); list = new ArrayList(); while (rs.next()) { Product product = new Product(); product.setProductID(rs.getInt("productId")); product.setName(rs.getString("name")); product.setBrand(rs.getString("brand")); product.setPrice(rs.getFloat("price")); product.setPicture(rs.getString("picture")); product.setDescription(rs.getString("description")); product.setType(rs.getString("type")); list.add(product); } } catch (Exception e) { e.printStackTrace(); } finally { this.closeAll(conn, pstmt, rs); } return list; } public Product finadProductByName(String name) { String sql = "select * from product where name=?"; Product product = null; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); pstmt.setString(1, name); rs = pstmt.executeQuery(); if (rs.next()) { product = new Product(); product.setProductID(rs.getInt("productId")); product.setName(rs.getString("name")); product.setBrand(rs.getString("brand")); product.setPrice(rs.getFloat("price")); product.setPicture(rs.getString("picture")); product.setDescription(rs.getString("description")); product.setType(rs.getString("type")); } } catch (Exception e) { e.printStackTrace(); } return product; } public List findAllProduct(String type) { List list = null; String sql = "select * from product where type=?"; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); pstmt.setString(1, type); rs = pstmt.executeQuery(); list = new ArrayList(); while (rs.next()) { Product product = new Product(); product.setProductID(rs.getInt("productId")); product.setName(rs.getString("name")); product.setBrand(rs.getString("brand")); product.setPrice(rs.getFloat("price")); product.setPicture(rs.getString("picture")); product.setDescription(rs.getString("description")); list.add(product); } } catch (Exception e) { e.printStackTrace(); } finally { this.closeAll(conn, pstmt, rs); } return list; } public List findAll() { List list = null; String sql = "select * from product "; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); list = new ArrayList(); while (rs.next()) { Product product = new Product(); product.setProductID(rs.getInt("productId")); product.setName(rs.getString("name")); product.setBrand(rs.getString("brand")); product.setPrice(rs.getFloat("price")); product.setPicture(rs.getString("picture")); product.setDescription(rs.getString("description")); product.setType(rs.getString("type")); list.add(product); } } catch (Exception e) { e.printStackTrace(); } finally { this.closeAll(conn, pstmt, rs); } return list; } public int deleteProductById(int productId) { int result = 0; String sql = "delete from product where productId=?"; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); pstmt.setInt(1, productId); result = pstmt.executeUpdate(); } catch (Exception e) { e.printStackTrace(); } finally { this.closeAll(conn, pstmt, rs); } return result; } public int updateProduct(Product product) { int result = 0; String sql = "update product set name=?,price=?,picture=?,description=?,type=? where productId=?"; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); pstmt.setString(1, product.getName()); pstmt.setFloat(2, product.getPrice()); pstmt.setString(3, product.getPicture()); pstmt.setString(4, product.getDescription()); pstmt.setString(5, product.getType()); pstmt.setInt(6, product.getProductID()); result = pstmt.executeUpdate(); } catch (Exception e) { e.printStackTrace(); } finally { this.closeAll(conn, pstmt, rs); } return result; } public int addProduct(Product product) { int result = 0; String sql = "insert into product values(?,?,?,?,?,?)"; try { conn = this.getConn(); pstmt = conn.prepareStatement(sql); pstmt.setString(1, product.getName()); pstmt.setFloat(2, product.getPrice()); pstmt.setString(3, product.getPicture()); pstmt.setString(4, product.getDescription()); pstmt.setString(5, product.getType()); pstmt.setString(6, null); result = pstmt.executeUpdate(); } catch (Exception e) { e.printStackTrace(); } return result; } }